134 
Correspondence . 
[January, 
means of a mechanical insert have 
shown me that the mechanism of 
flight may be obtained quite well 
with wings capable of changing their 
planes in consequence of the resist- 
ance of the air without being able to 
undergo helicoidal tors'on. Finally, 
as the bird which flies with registering 
apparatus (Figures 32 and 35) has 
furnished an elliptical tracing and not 
an 8, as in the inseCt, you see, Sir, 
that the reply to your note to the 
Academy of Sciences is not easy, and 
this accounts for my taking the 
liberty of addressing you to explain 
the situation and to beg of you to let 
me know as soon as possible how I 
can give you satisfaction without 
entering into a discussion which the 
reader would have great difficulty in 
following. May I ask you to send 
me a copy of your learned Memoir in 
order that I may study it more at 
leisure, and profit in the future by 
your labours in a subject so in- 
teresting.— Receive, Sir, &c.” 
Note. In this letter it will be per- 
ceived Professor Marey asks me to 
limit my claim to certain points in 
order to avoid discussion. Having, 
however, limited or restricted my 
claim, Professor Marey insinuates in 
his reply to Professor Coughtrie that 
I am not entitled to claim priority in 
the figure-of-8 and wave movements 
without at the same time stating that 
lie differs from me as to the manner 
in which these movements are pro- 
duced. In other words, he wishes it 
to be understood that the original 
discovery of the figure-of-8 and wave 
movements are of little account in 
comparison with his explanation of 
the manner of their production. In 
reality, however, as Professor Cough- 
trie showed in his article, and as I 
pointed out in a letter addressed to 
Professor Marey in 1870, there is 
little real difference between us, and 
Professor Marey deceives himself and 
his readers when he states that his 
theory is wholly opposed to mine. 
The figure-of-8 as originally pro- 
pounded by me includes, as I en- 
deavoured to show in my letter of 
1870, not only all the essential 
features of Professor Marey’s hypo- 
thesis, but even its details. 
I have described and represented 
the figure-of-8 made by the margins 
of the wing (figs. 2 and 3 of present 
communication) ; Professor Marey 
has described and represented the 
figure-of-8 made by the tip of the 
wing (fig. 5 of present communica- 
tion). If, however, the margins of 
the wing make figures-of-8 during 
extension and flexion and during the 
down and up strokes, it is obvious 
that the tip of the wing, or any point 
between the margins, will also make 
a figure-of-8 ; further, that the arrows 
indicating these movements will 
point in opposite directions. There 
is no escaping from this conclusion. 
However incredible it may appear, 
Professor Marey in his letter to the 
French Academy in reply to my 
reclamation completely ignored these 
explanations, touched lightlv upon 
the numerous points of resemblance, 
and emphasised the minor and sup- 
posed points of difference. He has 
wittingly or unwittingly persisted in 
making one half of my figure of 8 
represent the whole, and has erro- 
neously stated that in my figure of 8 
the arrows all point in one direction ; 
whereas in the completed figure they 
point in opposite directions as indi- 
cated at fig. 4 of present communica- 
tion. My figure of 8 when completed, 
and it must be completed according to 
the text, is identical with that subse- 
quently given by Professor Marey. I 
feel aggrieved at this treatment, as 
Professor Marey must be well aware 
that the part cannot in any case 
stand for the whole. With a perse- 
verance and perversity worthy of a 
better cause Professor Marey even 
goes the length of stating that he has 
accurately counterdrawn what he 
designates my suppressed figure in 
the English edition of his “Animal 
Mechanism ” (page 201, figure 86). 
It is quite true be has drawn and 
inverted my half figure, but, as Pro- 
fessor Coughtrie points out, he has in 
so doing totally misrepresented my 
views. One of two things is quite 
obvious, either Professor Marey does 
not even now understand the rationale 
of the figure of 8 as originally de- 
scribed and delineated by me, or (and 
I should be sorry to adopt this con- 
clusion) he wilfully distorts and 
mixes up the details. It may be well 
to mention at this sta^e that while 
Professor Marey is aware that the 
wing of the inseCt makes a figure-of-8 
